1. Field of the Invention
The present invention relates to an arrangement for pressure adjustment in a veneer assembling machine. The veneer assembling machine has at least two conveying units which include alternatingly raisable and lowerable heating and conveying rails which are arranged parallel next to each other on transverse support members. Each rail has on the input side and the output side of the veneer assembling machine a cylinder each to which a pressure medium can be admitted.
2. Description of the Prior Art
An arrangement of the above-described type has become known from Swiss Pat. No. 425,182. In this arrangement, the same adjustable pressure of a medium can be admitted to all pressure cylinders.
However, it has been found that when veneers are assembled and glued together into a material web in the above-described arrangement, the veneers do not assume a straight-line position after a period of time. Rather, the veneers deviate obliquely or in an arc-shape laterally to one and/or the other side. The reasons therefore may be different frictional conditions existing at the heating and conveying rails which may be due to dirt which accumulates over the time.
Such an oblique arrangement of the veneer pieces in feeding direction may particularly occur when the veneer pieces are not exactly parallel. This may lead to problems in subsequently arranged treatment units and/or may lead to obliquely cut veneer sheets.
When the veneer pieces are fed into the machine manually, this oblique positioning of the veneer pieces can be compensated by intermediately placing veneer pieces which are not entirely parallel. Of course, this is not possible in an automatic machine with feeding unit.
It is, therefore, the object of the present invention to provide an arrangement of the above-described type in which a rectilinear passage of the veneer pieces through the machine and a straight veneer web are possible even in an automatic operation.